Narrow and Broad band O2 sensors and open vs close Options

[lmcchesney]

Sorry guys, but I've been doing some reading again. Dave, you and I have had some of this discussion before and I would respect your continued thoughts on this setup. The crux of the matter requires understanding of the circuit utilized to turn the lamba analog data into useful information. Well, here goes.
O2 sensors in a distal position provides indirect input for the estimation of the A/F ratio seen by the engine. This information is useful in defining a lean or rich mixture seen by the sensor for the most recent peroid of time. Broad band O2 sensors are capable of producing a wide range of output voltages which can be inturpeted for measuring the ratio. In fact, the output from broad band sensors can be feed into the Electronic Control Unit several times a second. This allows for real time adjustment of the A/F mixture. Thus output from the O2 sensor is recieved as input by the ECU which inturn alters injector time/volume to preprogramed mixture. This feedback/adjustment defines a closed loop system.
Narrow band O2 sensors also read A/F ratios. However, A/F mixtures ranging from 13.7:1 to 14.4:1 results in a change in voltage output from lowest to highest (0.1v to 1.0v).
If you use a analog voltmeter or equalivernt A/F gague, the response rates are such that your readings bounce requiring seat of the pants estimate as to where the mean is.
However, with the use of circuitry involving a IC unit, the voltage output can be lengthed to a series of LED's.
My question, can not a narrow band O2 sensor be utilized to monitor A/F ratios throughout the power band. Noting the results, provide information for enrichment/leaning in the adjustable ranges of D-jet. ie, idle, partial throttle and WOT.
Cannot in dash monitoring with such an A/F circuit be helpful to identify serious alterations in the engine and prevent damage from excessively lean running?
Cannot the useful information from such an A/F monitor be inproved by silmiltaneous monitoring of CHT/oil temp?
I still do not understand the advantages of a broad band O2 sensor when used in a open loop system.
I cannot also see the significant advantage of a heated O2 sensor for monitoring the A/F ratios during that first 3 minutes.
Thanks,
L. McChesney

[airsix]

Heating the NBO2 won't get the temperature stable enough to make the readings useable. You will have to bite the bullet and pick up one of the setups pictured earlier.

the Daves are right. This was my experience. The NBO2 I talked about above was a heated one. Reputed by others (auto-groups like this) to be the best NBO2. Bosch, sorry - don't have the Bosch #, but it's a Napa part # OS204 for 86 Ford Escort.

Anyway, my finding is that the NBO2 are too influenced by temp, and too slow to react for useful tuning. In 20 minutes with the wideband I was able to do more for my car than I did in a YEAR with the NBO2.

-Ben M.

ps - This morning I made some tweaks based on the data I logged last night. WOT mixture now stays between 12.2-12.5:1 and the car is running great (autocrossed today). I'm going to fire off an email to the guys at Inovate Motorsports to thank them for making a reasonably priced WBO2 that works so well.